1. The Field of the Invention
The present invention relates generally to medical devices and methods. More specifically, embodiments of the invention relate to introducer sheaths and methods of making.
2. The Relevant Technology
A wide variety of sheaths have been developed for use in medical procedures. Sheaths are often used, for example, to access a vessel or artery to allow a surgical procedure to be performed. Sheaths are also used for medical procedures that utilize catheters such as, angioplasty or stenting. In practice, the introducer sheath is generally inserted into the patient's vasculature using the modified Seldinger technique. In the Seldinger technique, a needle is first inserted into the vessel and a guidewire then follows through the needle. Next, the needle is removed and a sheath/dilator combination is advanced over the guidewire. The dilator expands the puncture in the vessel to a size suitable to receive the distal end of an introducer sheath. After the distal end of the sheath is disposed within the vessel, the dilator and guidewire are removed, thereby allowing access to the vessel lumen or other body lumen via the inserted introducer sheath.
Conventionally, introducer sheaths are formed of three or more components that require assembly: a sheath portion, a hub, and a hemostasis valve disposed within the hub. A suitable example of such an assembly is shown in U.S. Pat. No. 5,807,350, which shows an introducer sheath having a construction similar to that described above, the entirety of which is hereby incorporated by reference.
Sheaths such as that described above are generally constructed of multiple pieces that must be assembled to form the sheath. Because the sheath is assembled from separate components, it is often difficult to align the lumen of the distal sheath portion with the lumen of the hub. As a result, additional time must be taken during manufacture to ensure alignment thereby leading to increased costs.
In some instances, the hub at the proximal end of the introducer sheath may be overmolded over the elongated sheath portion. While overmolding may produce a stronger sheath, there is the possibility of damaging a portion of the introducer sheath during the overmolding process. In addition to the cost of the overmolding process, the entire introducer sheath would then have to be discarded. There is a therefore a need for a new introducer sheath having lower manufacturing costs.